import numpy as np
arr1 = np.zeros(2)
print('一维数组arr1; \n', arr1)
arr2 = np.zeros((2, 3))
print('二维数组arr2: \n', arr2)
arr3 = np.ones(3)
print('一维数组arr3: \n', arr3)
arr4 = np.ones((3, 3))
print('二维数组aee4: \n', arr4)
arr5 = np.empty(4)
print('一维数组arr5: \n', arr5)
arr6 = np.empty((3, 4), dtype='int')
print('二维整数数组arr6: \n', arr6)

